Super Chevy
Click here to find out more!

Sudden loss of power at freeway speed

  
Super Chevy
Item Posts    Sort Order

Sudden loss of power at freeway speed

 
73novaguy 73novaguy
I love my Chevy Chevette! | Posts: 2 | Joined: 11/12
Posted: 11/08/12
07:51 AM

I was on the freeway, punched it, then had a sudden loss of power. It sputtered and basically died. I coasted over to shoulder, blue smoke came out the tailpipes and under the hood. I could not restart - had to be towed. I had this happen 6 months ago and I replaced the mechanical fuel pump and added a fuel pressure regulator. The carb was dialed in as well. All was fine until now. I checked the inline fuel filter - it's clean.
Any thoughts on what is the cause? This is totally ridiculous and unacceptable. Yes, I can have it towed to a shop for diagnostics and repairs but I am hoping for an easy fix?
Thank you. Confused  

waynep71222 waynep71222
My first time was in a Chevy | Posts: 218 | Joined: 04/12
Posted: 11/08/12
03:44 PM

why not do a full flow fuel pump output test...

disable the ignition system

disconnect the fuel line At the carb...    extend the disconnected tube with a section of fuel hose...

take a clean clear 2 or 3 liter plastic soda bottle and extend the fuel line into that..

while you are holding the fuel line in the neck of the bottle... have a friend crank the engine for 15 seconds while you observe the pulses of fuel from the end of the hose...

you should have nice full pulses...   not diminishing..

at the end of 15 seconds.. you should have at least a PINT of fuel in the bottle...

please check it with a magnet to the side of the bottle that there is no metallic dust in the gasoline..

this is just the first step in testing...

you could have a clogged strainer in the tank..

you could have a hole in the fuel tubing allowing air in..

you could have a kinked hose or a crimped line... reducing flow..

you could have sediment in the fuel pump check valves...

you could have a restriction in the fuel pressure regulator..

you could have a clogged fuel filter inside the carb inlet..  

pepsi1 pepsi1
Big Block power for the win | Posts: 940 | Joined: 03/11
Posted: 11/08/12
07:42 PM

You said you didn't hear any noise ie the engine had spun a bearing.So with that said.

Go to the fuel pump. That is the only logical thing that will make an engine lay down like that. Do like Wayne said check the out-put of your fuel pump.

Bob  

73novaguy 73novaguy
I love my Chevy Chevette! | Posts: 2 | Joined: 11/12
Posted: 11/09/12
12:32 AM

Thanks for your info.
Upon further checking, I have fuel in the carb bowls I can see fuel in the sight windows. I then changed my focus from fuel system to a spark issue. I found that the positive wire connector on the Mallory electronic ignition was badly corroded and loose. The wire fell out of the connector as I unloosened the nut. I replaced that and the engine fired right up. Did a 5 minute test drive - all is fine.
No spark to drive the distributor to plugs, etc. I hope this is all it was.
I'm gonna pull a spark plug or two tomorrow. If black and wet, I'll replace them and do an oil change as well for contamination issue. Thanks again! Smile  

pepsi1 pepsi1
Big Block power for the win | Posts: 940 | Joined: 03/11
Posted: 11/09/12
06:37 PM

Nova guy

Glad to hear you found your problem.

  I had 2 race cars.66 ChevyII and a 68 Camaro.I was going in for a knee operation. I had MSD-6AL ignitions in both.Long story short. I backed off the rocker arms to releave the valve spring pressure. I normally do this when anytime they are going to sit for more then a few weeks. (Just something I ***
  About 8 month's later I set the valves put fresh batteries in each. The Camaro fired right up. The ChevyII drove me crazy. It had NO Spark. Now all I did was remove the connectors from the coil and reinstall them and it fired up.
  I don't know what it is with does aftermarket Ignitions why they act that way? I had an old dual point Corvette distributor and never had a problem. Put them in and they have some much more spark potential,they are better.
  All I did was take the batteries out and releve the valve spring pressure.???

Bob